How-To: Quieting a Creaky Bike with Art's Cyclery
2

There you are, cruising along and feeling fit on your favorite scenic climb, the rhythm of your breathing matching your smooth and steady cadence. In this trance-like state, the world around you slips away, your existence distilled to timing pedal strokes with your inhalation and exhalation. And then, it starts. At first quiet and unnoticed, by the time it enters your consciousness, there is no way you can finish your ride until you have found it’s source. It is the dreaded creak.
More creaks are caused by cranks and bottom brackets than by any other source, but the majority of creaks originate somewhere else. To narrow down the source of the creak, follow this tried and true list of quick tests.
If the creak stops when you pedal out of the saddle, its source is your saddle or seat post. Pull the seat post out of the frame, thoroughly clean the post and seat tube, and apply lubricant compatible with your frame material. If this doesn’t stop the creak, remove your saddle from the seat post, clean and lightly lubricate the saddle rails, and reinstall the saddle, torquing to the appropriate specification.
If the bike creaks when you compress the suspension, or while standing on the pedals without pedaling, your suspension is the problem. It is time to clean and maintain your pivots, pivot hardware, and shock bushings.
Does it creak when you torque on the bars while standing in front of the bike? Then your stem or headset is likely the source. Clean, regrease, and retorque the assembly. If you have the correct tools and knowledge, knock out the headset cups to clean and regrease them before reinstalling, or have a qualified mechanic do it. If this doesn’t solve the issue on a front-end creak, your fork steerer might be the culprit. Steerer tubes sometimes creak where they are pressed into the fork crown. You can check this by putting the fork steerer in a vice and rocking the fork back and forth. If a loose steerer is causing the creak, you’ll need a new upper fork assembly.
If your bike still creaks while pedaling after eliminating these problems, check the easy stuff first by re-torquing axles, derailleur hangers, chainring bolts, and suspension bolts. Housing ferrule/cable stop interfaces can also be a source of creaks so they are worth checking too.
If this doesn’t work, then pull your bottom bracket. Inspect the bearings and crankset to look for damage. Clean, re-grease, and reassemble everything before torqueing it all down to the manufacturer’s torque specification.
If it still creaks, rebuild your suspension components while looking for damaged bearings and fasteners; it’s probably time for a suspension service anyway. Grease and torque everything after replacing damaged or worn parts.
If none of this cures your creak, check your bike for cracks. Start by looking at the welds on an alloy bike, and anywhere there are threaded inserts or reinforcing sleeves in a carbon frame, such as the bottom bracket or headset. If your search fails to turn up any cracks, you might need to just mellow out. Of course, you could be looking for cracks in the wrong place, and might want to consider getting your head examined instead.